CVE-2005-4690 in Movable Type
Summary
by MITRE
Six Apart Movable Type 3.16 allows local users with blog-creation privileges to create or overwrite arbitrary files of certain types (such as HTML and image files) by selecting an arbitrary directory as a blog s top-level directory. NOTE: this issue can be used in conjunction with CVE-2005-3102 to create or overwrite arbitrary files of all types.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/01/2017
The vulnerability described in CVE-2005-4690 represents a critical directory traversal and arbitrary file creation flaw within Six Apart Movable Type 3.16 blogging platform. This security weakness specifically targets the blog creation functionality and allows authenticated local users with blog-creation privileges to manipulate the file system in unintended ways. The vulnerability stems from insufficient input validation and directory path handling during the blog setup process, where users can specify arbitrary directory paths for their blog's top-level directory. This flaw enables attackers to bypass normal file system access controls and potentially overwrite or create files in locations where they should not have write permissions. The issue is particularly dangerous because it can be combined with CVE-2005-3102 to extend the scope of file manipulation capabilities beyond just HTML and image files to include all file types.
The technical implementation of this vulnerability involves the manipulation of directory path parameters during blog creation. When users specify a top-level directory for their blog, the application fails to properly sanitize or validate the input path, allowing directory traversal sequences or absolute paths to be used. This weakness directly relates to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks. The vulnerability operates at the application layer and requires local authentication, making it a local privilege escalation or lateral movement vector within the context of the system. Attackers can exploit this by creating blogs with malicious directory paths that point to system directories or other users' files, potentially leading to unauthorized file modification or creation.
The operational impact of CVE-2005-4690 extends beyond simple file manipulation to encompass potential system compromise and data integrity violations. Local users with blog creation privileges can leverage this vulnerability to overwrite critical system files, inject malicious content into existing files, or create backdoor files that could persist across system reboots. The combination with CVE-2005-3102 creates a particularly dangerous scenario where attackers can gain the ability to write any type of file to any location, effectively providing a complete system compromise capability. This vulnerability undermines the principle of least privilege and can be used to establish persistent access or cause denial of service conditions. The impact is significant for organizations relying on Movable Type platforms, as it allows unauthorized users to modify or corrupt system files that should be protected from user modifications.
Mitigation strategies for CVE-2005-4690 should focus on implementing proper input validation and access control mechanisms within the blogging platform. System administrators should immediately apply available patches or updates from Six Apart to address this vulnerability. Additionally, implementing strict directory path validation and ensuring that blog creation functionality only allows paths within designated directories can prevent exploitation. The use of privilege separation and mandatory access controls can limit the damage that can be caused by local users with blog creation privileges. Organizations should also implement monitoring and logging of blog creation activities to detect suspicious directory path usage. This vulnerability highlights the importance of secure coding practices and input validation, particularly in applications that handle user-provided directory paths. The ATT&CK framework categorizes this as a privilege escalation technique through local system manipulation, and organizations should consider implementing network segmentation to limit the potential impact of such local vulnerabilities. Regular security audits and penetration testing should be conducted to identify similar path traversal vulnerabilities in other applications and systems.